The present invention relates to gas discharge display apparatus. More particularly, the invention relates to an AC plasma display panel providing a looped rotary display due to shift operation of discharge spots.
Mechanical displays or electronic displays have been used as indicators of various measuring instruments and as time displays of clocks. However, mechanical indicators of the type utilizing a pointer are very complicated in configuration and occupy large spaces. Furthermore, electronic displays functioning as indicators capable of displaying values analogously or digitally have very complicated driver circuits.
On the other hand, an AC driven plasma display panel having a discharge spot shifting function is well known as gas discharge display apparatus. This type of plasma display panel is described in pending U.S. Pat. Application Ser. No. 277,564, now U.S. Pat. No. 3,944,875, filed by Urade et al and entitled "Gas Discharge Device Having a Function of Shifting Discharge Spots". The plasma display panel described in the application is so constructed that the discharge spot generated at one end of the panel based on the write signal is self-shifted toward the other end of the panel by sequential switching of a multiphase operating voltage for the shift electrodes. The self-shifting plasma display has the excellent advantage that the configuration of the driver circuit may be distinctively simplified as compared with that of the conventional plasma display of matrix type. The currently known self-shifting plasma display device is deficient, however, since it cannot provide a looped rotary display like various kinds of meters and clocks.
The principal object of the invention is to provide gas discharge display apparatus which is capable of providing a looped rotary display.
An object of the invention is to provide gas discharge display apparatus of simple circuit structure which can rotate the discharge spot.
Another object of the invention is to provide electronic analog gas discharge display apparatus which can be used in the same manner as the meter indicator of various measuring instruments and the hands of a clock.
Still another object of the invention is to provide gas discharge display apparatus which can rotate the discharge spots for display at respectively different speeds in a plurality of channels arranged as concentric circles.
Yet another object of the invention is to provide an improved self-shifting plasma display which can shift the discharge spot in accordance with an input signal up to a predetermined position along the closed loop of a predetermined shift channel.